The present invention relates to a method and apparatus of producing a printer head, which forms ink outlets of an ink-jet printer by forming apertures shaped in a reverse taper to the laser irradiating direction, and also provides an aperture processing device used for the method and apparatus.
At a head portion of the ink-jet printer, a metal orifice plate 3 at which a plurality of orifices 2 are formed as ink outlets is bonded to a plurality of ink chambers 1 as shown in FIG. 13. The ink chambers 1 are sectioned by dissepiments 4, and ink drops are discharged from the orifice 2 by a discharging mechanism (not shown) for executing a predetermined ink discharging as shown in FIG. 14. As for the discharging mechanism, for example, the bubble-jet system and the kayser system comprising a piezoelectric vibration plate are known.
The orifice 2 of such an ink-jet printer is formed to have a diameter of about 30 microns, and a plate of Ni, covar and the like having the thickness of about 50 xcexcm is used as the metal orifice plate 3.
Generally, a plating method called the electrotyping is employed for the production of the metal orifice plate 3. When the metal orifice plate 3 is bonded to the printer head portion, in the following printer head producing process, the center of the orifice 2 and the center of the ink chamber 1 are shifted by the amount xcex94A. In other words, it is difficult to maintain the accuracy in positioning the orifices 2 of the metal orifice plate 3 and the ink chambers 1. In addition, the orifice 2 is filled up with a bonding agent 5 as represented by B.
To solve this problem, a processing method of bonding the orifice plate to the head portion of the printer and then opening the orifice 2 by the laser light is proposed. In this case, the mask on which the aperture pattern is used.
Incidentally, when the orifice is processed by the mask, the laser light is irradiated not only to the aperture pattern of the mask, but also to almost the entire surface of the mask. For this reason, the laser light passing through the aperture pattern forms an image on the orifice plate and thereby processes the orifice.
The accuracy in the diameter of the orifice is determined in accordance with the accuracy in the mask, and therefore, the mask is required to be produced at high accuracy, and a thin metal plate having a thickness of less then 50 xcexcm is used to keep the accuracy.
Orifices 6a are formed in the staggered shape on a mask 6 as shown in FIG. 15. That is, the orifices 6a are arranged with a predetermined interval along the longitudinal direction of the band-shaped mask 6, and two of the orifices constitute one group. Two circular apertures 6a in each group are displaced by the amount xcex94y in the width direction. The reason is that the shift of timing of the control in the paper scanning direction can be canceled by shifting the timing of the control of the ink discharge for every two apertures.
The laser light beam irradiated onto the mask 6 is shaped in a band so that the orifices 6a are positioned in the range of the irradiation as represented by part A of oblique lines in the figure.
However, when the orifices 6a are formed in the staggered shape on the mask 6, the width of the laser light beam irradiated on the mask 6 must be large in accordance with the amount of shift xcex94y of the orifices 6a. For this reason, the energy density per unit area in the beam shape of the laser light is lowered, and the efficiency of use of the laser light energy is lowered in accordance with this. In other words, a high power laser device is required in accordance with lowering of the efficiency of use of the laser light energy.
Further, if the beam shape of the laser light is made large and its energy is increased, the energy which is input to the mask 6 is increased, and therefore, the mask 6 formed of a thin metal plate is often deformed or damaged.
The present invention provides a method and apparatus of producing a printer head capable of irradiating an aperture pattern formed in a staggered shape onto a mask without lowering the efficiency of use of the laser light energy, and also provides an aperture pattern.
A method of producing a printer head, according to claim 1, comprises the steps of bonding a plate to be processed which is formed of a macromolecular material, on a printer head housing on which a plurality of ink grooves are formed; shaping laser light in a predetermined beam; allowing the laser light to pass through a mask on which an aperture pattern are formed in the staggered shape, in accordance with an opening shape of the plate; splitting the laser light in accordance with the aperture pattern before the step of allowing the laser light to pass; and forming an image of the laser light passing through the mask on the plate by an image forming optical system and forming an opening on the plate.
According to the present invention, the aperture pattern formed in the staggered shape can be irradiated onto the mask without extending the beam shape of the laser light, and therefore, the efficiency of use of the laser light energy can be enhanced.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.